With the targeted focus on integrating security into operational readiness
stances in some enterprises these days, I was curious if there was guidance
out there on the security metrics that some consulting firms and internal
security teams are working to establish.

computername\none is a special group (hidden in the local users/groups mmc; try creating a user or a group named None on Windows, it will fail with an error group exists). None equates to the domain users in AD.
Read Keith Brown's "Programming Windows Security" (if it is still available) to understa

I have a question on something I saw on my computer today. I'm on a
Windows Vista. I was looking at some of the "properties" of some
folders in my "Public" folder and clicked on the "Security" tab. Then
I noticed my usual login user, "Everyone", and one other user, whose
id seemed to be S-1-5-